Treating to target: a strategy to cure gout

Predicting Gout Flares in People Starting Allopurinol Using the Start-Low Go-Slow Dose Escalation Strategy

OBJECTIVE

The study objective was to determine predictors of gout flare when commencing allopurinol using the "start-low go-slow" dose escalation strategy.

METHODS

A post hoc analysis of a 12-month double-blind placebo-controlled noninferiority trial with participants randomized 1:1 to colchicine 0.5 mg daily or placebo for the first six months was undertaken. Multivariate logistic regression models were used to identify independent predictors of gout flares in the first and last six months of the trial.

RESULTS

Multivariable analysis revealed a significant association between risk of a gout flare in the first six months and flare in the month before starting allopurinol (odds ratio [OR] 2.65, 95% confidence interval [CI] 1.36-5.17) and allopurinol 100 mg starting dose (OR 3.21, 95% CI 1.41-7.27). The predictors of any gout flares in the last six months of the trial, after stopping colchicine or placebo, were having received colchicine (OR 2.95, 95% CI 1.48-5.86), at least one flare in the month before stopping study drug (OR 5.39, 95% CI 2.21-13.15), and serum urate ≥0.36 mmol/L at month 6 (OR 2.85, 95% CI 1.14-7.12).

CONCLUSION

Anti-inflammatory prophylaxis when starting allopurinol using the "start-low go-slow" dose escalation strategy may be best targeted at those who have had a gout flare in the month before starting allopurinol and are commencing allopurinol 100 mg daily. For those with ongoing gout flares during the first six months of starting allopurinol who have not yet achieved serum urate target, a longer period of prophylaxis may be required.

A machine learning-based prediction model for gout in hyperuricemics: a nationwide cohort study

OBJECTIVE

To develop a machine learning-based prediction model for identifying hyperuricemic participants at risk of developing gout.

METHODS

A retrospective nationwide Israeli cohort study used the Clalit Health Insurance database of 473 124 individuals to identify adults 18 years or older with at least two serum urate measurements exceeding 6.8 mg/dl between January 2007 and December 2022. Patients with a prior gout diagnosis or on gout medications were excluded. Patients' demographic characteristics, community and hospital diagnoses, routine medication prescriptions and laboratory results were used to train a risk prediction model. A machine learning model, XGBoost, was developed to predict the risk of gout. Feature selection methods were used to identify relevant variables. The model's performance was evaluated using the receiver operating characteristic area under the curve (ROC AUC) and precision-recall AUC. The primary outcome was the diagnosis of gout among hyperuricemic patients.

RESULTS

Among the 301 385 participants with hyperuricemia included in the analysis, 15 055 (5%) were diagnosed with gout. The XGBoost model had a ROC-AUC of 0.781 (95% CI 0.78-0.784) and precision-recall AUC of 0.208 (95% CI 0.195-0.22). The most significant variables associated with gout diagnosis were serum uric acid levels, age, hyperlipidemia, non-steroidal anti-inflammatory drugs and diuretic purchases. A compact model using only these five variables yielded a ROC-AUC of 0.714 (95% CI 0.706-0.723) and a negative predictive value (NPV) of 95%.

CONCLUSIONS

The findings of this cohort study suggest that a machine learning-based prediction model had relatively good performance and high NPV for identifying hyperuricemic participants at risk of developing gout.

Urate-lowering agents do not have clinically relevant negative effects on sperm quality and reproductive hormones in men with gout: a prospective open-label cohort study

OBJECTIVE

The objective of this study was to analyze and compare the effects of different urate-lowering agents on testicular functions in men with gout in a clinical setting.

METHODS

In this prospective cohort study (Clinical Trial Registration Number: NCT04213534), a total of 49 male patients aged 18-45 years with gout were enrolled. They were divided into three groups and received treatment with either allopurinol, febuxostat or benzbromarone for a duration of 3 months. Semen parameters, reproductive hormones and biochemical assessments were evaluated at baseline, month 1, and month 3.

RESULTS

Overall, 40 individuals (81.6%) completed the follow-up visits. In allopurinol group, there were no significant differences in semen parameters from baseline to month 3. Most of sperm parameters in febuxostat group did not show notable changes, except for a decrease in sperm motility at month 3(33.6%, [22.9-54.3] vs 48.4%, [27.4-67.6], p = 0.033). However, the total motile sperm count did not differ significantly after febuxostat treatment. Surprisingly, administration of benzbromarone resulted in improved sperm concentration (37.19 M/mL, [29.6-69.92] vs 58.5 M/mL, [49.8-116.6], p = 0.001). There were no significant changes observed in sperm DNA integrity and reproductive hormones in the three groups from baseline to month 3. The incidence of adverse events did not differ significantly among the three groups as well.

CONCLUSION

This study is the first to demonstrate that urate-lowering agents, allopurinol and febuxostat, do not have clinically relevant negative effects on sperm quality and reproductive hormones in men with gout, and benzbromarone presents improving sperm concentration. Results provide important preliminary guidance for the development of reproductive health management guidelines for patients RCID with gout.

Comparison of the efficacy and safety of benzbromarone and febuxostat in gout and hyperuricemia: a systematic review and meta-analysis

OBJECTIVE

Urate-lowering therapy (ULT) is widely recognized as the primary treatment for hyperuricemia and gout. Xanthine oxidase inhibitors (XOI), particularly febuxostat, have gained popularity as a frontline approach. However, the divergent efficacy and safety between febuxostat and the traditional ULT drug, benzbromarone, remain poorly understood. This knowledge gap necessitates a comprehensive analysis and evidence update to guide drug selection for physicians and patients.

METHOD

We conducted a systematic analysis by extracting relevant clinical studies from four medical literature databases. Forest plots, funnel plots, sensitivity analysis, Egger's test, and subgroup analysis were utilized to compare relevant indicators.

RESULTS

The advantages and disadvantages of the two drugs were evaluated based on various indicators such as serum uric acid (SUA), triglyceride (TG), urinary uric acid (UUA), white blood cell count (WBC), total cholesterol (TC), blood urea nitrogen (BUN), alanine aminotransferase (ALT), aspartate aminotransferase (AST), estimated glomerular filtration rate (eGFR), and serum creatinine (SC). Benzbromarone demonstrated better efficacy in rapidly reducing SUA levels and inhibiting inflammation for hyperuricemia and gout patients. Febuxostat was slightly less effective in lowering SUA, but there was no significant difference in its impact on liver and kidney function after long-term use.

CONCLUSION

This study highlights the superiority of benzbromarone in rapidly reducing SUA and inhibiting inflammation. Febuxostat shows comparable effects on liver and kidney function after long-term use. These findings provide valuable insights for clinicians and patients in drug selection. Key Points • Benzbromarone stands out as a highly effective treatment for hyperuricemia and gout, offering rapid reduction of serum uric acid levels and potent anti-inflammatory effects. • When it comes to long-term use, febuxostat demonstrates comparable effects on liver and kidney function. This provides reassurance for patients who require extended treatment duration. • Moreover, our study goes beyond previous research by presenting a more comprehensive and detailed analysis.

High-normal serum uric acid predicts macrovascular events in patients with type 2 diabetes mellitus without hyperuricemia based on a 10-year cohort

BACKGROUND AND AIMS

The upper limits of normal serum uric acid (SUA) or the lower limits of hyperuricemia were frequently set at 420 or 360 μmol/L (7.0 or 6.0 mg/dL). We aimed to explore the association between high-normal SUA (360 ≤ SUA≤420 μmol/L) and incidence of macrovascular and renal events based on a 10-year cohort with type 2 diabetes mellitus (T2DM) to explore which cut-off was more appropriate.

METHODS AND RESULTS

A total of 2988 patients with T2DM without hyperuricemia (SUA≤420 μmol/L) were included and followed up. Cox proportional hazards models and restricted cubic spline regression were used to evaluate the relationship between baseline SUA (as continuous and categorical variable) and macrovascular and renal events. Patients were grouped as low-normal (SUA<360 μmol/L) and high-normal groups based on baseline SUA, and the latter group had higher incidence of macrovascular events. Multivariate Cox regression analysis indicated that baseline levels of SUA were significantly associated with cardiovascular (HR = 1.385, 95%CI:1.190-1.613, P < 0.001) and peripheral vascular events (HR = 1.266, 95%CI:1.018-1.574, P = 0.034), and the linear association existed. Moreover, fully adjusted multivariable Cox analyses indicated high-normal SUA increased the risks of cardiovascular (HR = 1.835, 95%CI:1.319-2.554, P < 0.001) and peripheral vascular events (HR = 1.661, 95%CI:1.000-2.760, P = 0.050) compared to low-normal SUA.

CONCLUSIONS

Baseline SUA levels were positively associated with cardiovascular and peripheral vascular events, and high-normal SUA increased the risks of these events in patients with T2DM even without hyperuricemia. A threshold value for SUA of 360 μmol/L should be more appropriate in terms of predicting macrovascular events risks compared to the value of 420 μmol/L.

Epidemiology and risk factors associated with gout control among adult Asians: a real-world retrospective cohort study

Background

Gout is associated with significant morbidity and mortality, yet suboptimal gout control remains a problem globally. Identifying the risk factors associated with poor gout control among patients in primary care allows targeted interventions to improve their clinical management. This study aimed to determine the prevalence of poor gout control and its associated demographic and clinical factors among urbanized community-dwelling Asian patients.

Methods

This retrospective study was based on data extracted from the electronic medical records of 8 public primary care clinics in Singapore. Patients with a diagnostic code of gout who had 2 or more visits between 1st January 2018 and 31st December 2019 were included in the analysis. Data extracted included: demographics, anthropological measurements, comorbidities, serum uric acid levels and medication prescription. A patient is defined to have poor gout control if they suffer two or more acute gout attacks within a year. Chi-Squared test was used for categorical parameters. For continuous variables, univariate logistic regression analysis was first performed. Significant factors (p ≤ 0.1) were then included in the logistics regression model to account for confounders.

Results

A total of 7,970 patients and 24,624 visits were included in the analysis. The prevalence of poorly controlled gout was 28.2% (n = 2,244/7,970); only 46.3% of them (n = 1,039/2,244) were prescribed allopurinol and 13.4% (n = 301/2,244) were taking doses ≥300 mg. Using logistic regression, factors associated with poor gout control were: male gender [adjusted OR (AOR) =1.66, p < 0.001], Malay ethnicity (AOR = 1.27, p = 0.007), congestive heart failure (AOR = 1.64, p = 0.037). Patients prescribed allopurinol (AOR = 1.52, p < 0.001), NSAIDs (AOR = 2.76, p < 0.001) and corticosteroids (AOR = 2.83, p < 0.001) were more likely to have poorly-controlled gout.

Conclusion

Nearly 30% of patients had poor gout. Interventions should focus on male and Malay patients and those with congestive cardiac failure.

Multi-spectroscopic assay methods for concurrent determination of recent anti-gout combination, a comparative study

Recently, Chemometric calibration methods in spectrophotometric analysis are achieving significant attention in the quality control of resolving drug mixtures and pharmaceutical formulations containing two or more drugs with overlapping spectra. The simple univariate methods have been used over the last few decades and has proven to be highly efficient and easy to apply. In this study, a comparative study was performed between some univariate and multivariate methods to determine if chemometric methods can substitute univariate methods in pharmaceutical analysis. In this study, three chemometric techniques were compared to seven univariate techniques to resolve a mixture of mefenamic acid and febuxostat in their raw materials, dosage forms and spiked human plasma. Mefenamic acid and febuxostat were used together for treatment of gout. The applied chemometric methods are partial least squares (PLS), artificial neural network (ANN) and genetic algorithm partial least squares (GA-PLS), while the used univariate methods include first derivative, second derivative, ratio spectra, derivative ratio spectra, ratio subtraction, Q-Absorbance ratio and mean centering spectrophotometric methods. The ten proposed methods were found to be green, sensitive, and rapid. They are simple and did not require any pre-separation steps. The results of both univariate and multivariate approaches were statistically compared with the reported spectrophotometric methods using student's t test and ratio variance F-test. They were also compared with each other, using one-way analysis of variance (ANOVA). These methods were assessed and validated according to ICH guidelines. The studied drugs were analyzed in their pharmaceutical dosage forms and spiked human plasma with good recoveries using the developed methods, which qualify them for routine quality control of the studied drugs.

A multi-step approach to develop a "storytelling" intervention to improve patient gout knowledge and improve outpatient follow-up

Background

"Storytelling" interventions influence knowledge, attitudes and behavior to promote chronic disease management. We aimed to describe the development of a video "storytelling" intervention to increase gout knowledge and promote adherence to medications and follow-up care after an acute gout flare visit in the emergency department.

Methods

We developed a direct-to-patient storytelling intervention to mitigate modifiable barriers to gout care and promote outpatient follow-up and medication adherence. We invited adult patients with gout as storytellers. We utilized a modified Delphi process involving gout experts to identify key themes to guide development of an intervention. Using a conceptual model, we selected stories to ensure delivery of evidence-based concepts and to maintain authenticity.

Results

Our video-based storytelling intervention consisted of segments addressing modifiable barriers to gout care. Four diverse gout patients were recruited as storytellers and interviewed with questions that covered gout diagnosis and care. Eleven international gout experts from diverse geographic locations generated and ranked items they considered important messages to promote outpatient gout care follow-up and treatment adherence. Filmed videos were truncated into segments and coded thematically. Distinct segments that captured desired messages were combined to form a cohesive narrative story based on gout patient experiences that conveyed evidence-based strategies to manage gout.

Conclusions

Using the Health Belief Model, we developed a culturally appropriate narrative intervention containing "storytelling" that can be tested as an approach to improve gout outcomes. The methods we describe may be generalizable to other chronic conditions requiring outpatient follow-up and medication adherence to improve outcomes.

Superiority of Low-Dose Benzbromarone to Low-Dose Febuxostat in a Prospective, Randomized Comparative Effectiveness Trial in Gout Patients With Renal Uric Acid Underexcretion

OBJECTIVE

The predominant mechanism driving hyperuricemia in gout is renal uric acid underexcretion; however, the standard urate-lowering therapy (ULT) recommendation is first-line xanthine oxidase inhibitor (XOI), irrespective of the cause of hyperuricemia. This comparative effectiveness clinical trial was undertaken to compare first-line nontitrated low-dose benzbromarone (LDBen) uricosuric therapy to XOI ULT with low-dose febuxostat (LDFeb) in gout patients with renal uric acid underexcretion.

METHODS

We conducted a prospective, randomized, single-center, open-label trial in men with gout and renal uric acid underexcretion (defined as fractional excretion of urate <5.5% and uric acid excretion ≤600 mg/day/1.73 m2 ). A total of 196 participants were randomly assigned to receive LDBen 25 mg daily or LDFeb 20 mg daily for 12 weeks. All participants received daily urine alkalization with oral sodium bicarbonate. The primary end point was the rate of achieving the serum urate target of <6 mg/dl.

RESULTS

More participants in the LDBen group achieved the serum urate target than those in the LDFeb group (61% compared to 32%, P < 0.001). Rates of adverse events, including gout flares and urolithiasis, did not differ between groups, with the exception of greater transaminase elevation in the LDFeb group (4% for LDBen compared to 15% for LDFeb, P = 0.008).

CONCLUSION

Compared to LDFeb, LDBen has superior urate-lowering efficacy and similar safety in treating relatively young and healthy patients with renal uric acid underexcretion-type gout.

Surgical Treatment of Hand and Foot Gout Stone and Influence Factors on Prognosis

Purpose

To explore the technique of surgical treatment of hand and foot gout stone by using 3D CT reconstruction images and influence factors on prognosis.

Method

48 cases of hand and foot gout were treated surgically and retrospective analyzed. Before operation, we used 3D CT reconstruction images to check the accurate site and amount of uric acid (white chalk foam) deposition. Different surgical methods were applied depending on the different deposition site of urine acid stone. The frequency of gout attack and blood uric acid was compared before and after surgery. Patients were followed up to observe the recovery and recurrence and then analyzed the reason of unsuccessful healing.

Result

Sutures were removed 2 weeks after operation in all cases. The frequency of gout attack and blood uric acid of patients 3 months after operation was lower than those before operation, and the differences were statistically significant. Follow-up ranged from 1 to 3 years, with an average of 1.8 years. Three cases were not followed up. The remaining 45 cases were healed in the first stage. 40 cases had improved joint function, increased range of motion, and relieved discomfort after movement. 5 cases had no improvement in joint function after operation, and 3 of them had gout stone recurrence (nonoperative area) and were treated by second hospital operation.

Conclusion

Surgical treatment of gout stone in hand and foot under the guidance of three-dimensional CT reconstruction image can effectively alleviate the local symptoms of gout stone and improve the function of hand and foot. Deep tissue can be thoroughly washed by the pressure of pulse gun after resection of the lesion, which can reduce the incidence of gout stone. Malnutrition, hypoproteinemia, and residual urine acid in the wound are the main reasons for unsuccessful healing.

When underlying biology threatens the randomization principle - initial gout flares of urate-lowering therapy

Flare is the dominant feature of gout and occurs because of inflammatory response to monosodium urate crystals; prevention of gout flares should be the major goal of gout care. However, a paradoxical increase in the risk of flare following initiation of urate-lowering therapy presents considerable challenges for proving the expected long-term benefits of flare prevention in clinical trials. Nevertheless, excluding from enumeration flares that occur in the initial post-randomization period (which can last several months to 1 year) can threaten the core benefits of randomization: the characteristics of the remaining participants can differ from those who were randomized, introducing potential bias from confounding (both measured and unmeasured); participants who drop out or die are excluded from the analysis, introducing potential selection bias; and, finally, ignoring initial flares underestimates participants' experience during the trial. This Perspective discusses these issues and recommends measures that will allow for high-level evidence that preserves the randomization principle, to satisfy methodological scrutiny and generate robust evidence-based guidelines for gout care.

Change in serum urate level with urate-lowering therapy initiation associates in the immediate term with patient-reported outcomes in people with gout

OBJECTIVE

To examine the associations of changes in serum urate (SU) with health-related quality of life (HRQOL) in gout.

METHODS

We used the first 6-months of data from four interventional trials and one observational, open-label study of urate-lowering therapy (ULT) use. HRQOL were assessed at baseline and every 3-months, and SU was measured monthly. Primary outcome measures were Short-form 36 physical and mental component summary scores, Health Assessment Questionnaire Disability Index (HAQ-DI), Sheehan Disability Scale (SDS), Patient Global Assessment, and pain scores in the last week. Linear mixed models for each outcome were adjusted as appropriate for current SU, change in urate in the last month, number of flare-affected days in the last month, baseline BMI, age, comorbidities, sex, ethnicity, trial/study and treatment combination, and tophi status (fixed effects); subject, and the trial/study month were random effects.

RESULTS

Higher current SU correlated with reduced physical and mental HRQOL, and increased SDS and pain but not with HAQ-DI score. In the first 6-months of new/escalating ULT use, absolute change in SU levels associated with poorer outcomes on the HAQ-DI scale (β (95% CI) = 0.013 (0.007-0.019)) and poorer outcomes on SDS, SF-36 MCS, patient global and pain scales. Reduction of SU associated with poorer outcomes in all six measures.

CONCLUSION

High SU levels were associated with poorer HRQOL, pain and Sheehan disability score. Recent SU level fluctuations are associated with poorer outcomes, primarily driven by a reduction in SU. Clinical emphasis on slow rather than fast SU reduction and the routine use of effective, anti-inflammatory medications at ULT initiation/escalation may avoid short-term poor outcomes.

A stable and highly luminescent 3D Eu(III)-organic framework for the detection of colchicine in aqueous environment

The metal-organic framework materials have an important application as sensors. In this work, a microporous three-dimensional (3D) Eu(III)-organic framework (Eu-MOF), [Eu₂(3,5-bct)(phen)₂(ox)₂(H₂O)]·H₂O, was constructed from 3,5-bis(3'-carboxyphenyl)-1,2,4-triazole (3,5-H₂bct), oxalate (ox) and 1,10-phenanthroline (phen) as a luminescent sensor. The free volume was found to be 15.7% per unit volume ignoring the free water molecules. The Eu-MOF showed bright red light due to the emission at 622 nm (⁵D₀ → ⁷F₂ transition) of the Eu(III) with high quantum yield (QY, 52.51%). The Eu-MOF exerted high luminescence stability in common organic solvents as well as aqueous solutions within a wide pH range from 4 to 11. Based on the luminescent Eu-MOF, the sensing behavior for colchicine in the aqueous environment was studied. Highly selective and sensitive detection (LOD = 2.43 × 10^-5 mol L^-1) of colchicine was observed by the Eu-MOF even in the presence of potential interfering components. The sensing mechanism for colchicine was investigated by experimental and theoretical results. It is worth noting that a film (Film@Eu-MOF) prepared by loading Eu-MOF showed intense characteristic red light emission under UV light. The luminescence color changed immediately from red to colorless when the Film@Eu-MOF came in contact with colchicine. Highly sensitive and rapid detection of colchicine in wastewater was achieved using this Film@Eu-MOF, which could be identified by the naked eye. The experimental results suggest that the synthesized Eu-MOF has potential application as a luminescent sensing material for pollutants in the environmental system.

Exploring the Mechanism through which Phyllanthus emblica L. Extract Exerts Protective Effects against Acute Gouty Arthritis: A Network Pharmacology Study and Experimental Validation

Increased uric acid levels and inflammatory reactions are the main factors considered responsible for the development of gouty arthritis. Phyllanthus emblica L. (PEL) has several promising pharmacological properties, including anti-inflammation and antioxidation. However, only a few studies have investigated its use for treating acute gouty arthritis (AGA), and the mechanism of action of PEL has not yet been clarified. The aim of this study was to verify the protective effects of PEL against gout and explore its underlying mechanism through network pharmacology and animal experiments. The main active components of the extract from PEL including mucic acid, mucic acid lactone, gallic acid, ethyl hexyl phthalate, and glucose were identified by UPLC-ESI-qTOF-MS. Network pharmacological analysis results revealed 13 active compounds in PEL and 85 related targets for the treatment of gout. The core mechanism of action of PEL is mainly associated with inflammation-related pathways, including the HIF-1, PI3K-Akt, TNF, and NOD-like receptor signaling pathways. Previous studies revealed that the NOD-like receptor signaling pathway, especially the NLRP3 inflammasome, plays an important role in the pathogenesis of AGA; therefore, we mainly investigated the effect of PEL on the NLRP3/ASC/caspase-1 pathway in gout rats. In the animal experiments, PEL was shown to have a satisfactory antigout effect, as it effectively reduced uric acid (UA) and xanthine oxidase (XOD) levels. In terms of inhibiting AGA-associated inflammatory reactions, our results showed that PEL significantly decreased the expression of NLRP3 and caspase-1 in ankle synoviocytes as well as the levels of downstream inflammatory factors, such as TNF-α, IL-10, and IL-1β in serum. Moreover, the results of our study show that PEL reduced MMP13 expression in the ankle synovium. Overall, the results of this study indicate that PEL exerted a therapeutic effect against AGA. Reducing uric acid levels, inhibiting inflammation, and decreasing the expression of MMP13 may be responsible for the therapeutic effect of PEL, which suggests that PEL can be further developed as a drug for the treatment of gout.

A patient-centered gout information value chain: a scoping review

OBJECTIVE

To examine and identify the scope of research addressing health information requirements for gout patients using value chain analysis.

METHODS

Five electronic databases (PubMed, CINAHL, ERIC, PsycINFO, Embase, and Scopus) and grey literature (WorldCat) were searched in accordance with a published protocol. Only English language articles were included, with no limitations for date of publication. The findings of the 33 studies included for final analysis were subsequently divided into 6 groups according to the stages of the care delivery value chain their research most closely pertained to: screening/preventing (n = 2), diagnosing (n = 1), preparing (n = 7), intervening (n = 11), recovering/rehabilitating (n = 5), and monitoring/managing (n = 13).

RESULTS

The 33 studies focused on one or more of the following information phenotypes: 1) pathophysiology; 2) medical treatment; and 3) nonpharmaceutical interventions. Long term treatment adherence was a popular topic amongst studies that focused on gout patient education.

CONCLUSION

Based on the identified studies, gout patients are being told what to do, but are not being adequately educated regarding why recommended interventions are important or how to accomplish them.

PRACTICE IMPLICATIONS

This review provides a foundation to develop and evaluate personalized education materials using value chain analysis.

Serum uric acid variability increases the risk of postoperative chronic kidney disease in patients with renal cell carcinoma after radical nephrectomy

OBJECTIVE

Serum uric acid (SUA) level is associated with the progression of chronic kidney disease (CKD). However, little is known about the predictive value of SUA variability for postoperative CKD in patients with renal cell carcinoma after radical nephrectomy. We aimed to investigate the association of SUA variability with postoperative CKD in this population.

METHOD

85 patients with preoperative estimated glomerular filtration rate (eGFR)≥60 ml/min/1.73 m² were enrolled in this single-center retrospective study and followed up for at least 6 months. Intra-individual SUA variability was defined as the standard deviation (SD) of SUA and the patients were stratified into three groups according to the tertiles of SUA SD (the lower, middle and upper tertile). The association of SUA variability with postoperative CKD, defined as an eGFR<60 ml/min/1.73m², was analyzed by Cox proportional hazard models and Kaplan-Meier analyses.

RESULTS

After a median follow-up time of 24(10-43) months, 44(51.7%) patients developed postoperative CKD. Kaplan-Meier curves showed that patients in the lower tertile had a longer CKD-free survival time [median CKD-free survival time 74(52.2-95.8) months] than those in the middle tertile [38(19.2-56.8) months] and upper tertile [21(17.9-24.1) months] (overall generalized Wilcoxon test: P=0.001; lower vs middle tertile: P=0.001; lower vs upper tertile: P<0.001). Adjusted Cox analyses indicated that increasing SUA SD tertiles were associated with a higher risk of postoperative CKD independent of baseline SUA, mean SUA during follow-up and other confounding variables. Compared with patients in the lower tertile, the risk for developing CKD increased by 4.6-fold for patients in the middle tertile and 7.9-fold in the upper tertile, respectively.

CONCLUSION

Increasing SUA variability was associated with an increased risk of postoperative CKD in patients with renal cell carcinoma after radical nephrectomy.

Volumetric reduction and dissolution prediction of monosodium urate crystal during urate-lowering therapy - a study using dual-energy computed tomography

METHODS

Baseline and follow-up DECTs were performed under a standard ULT protocol. Monthly dissolution rates were calculated by simple and compound methods. Correlations with average SU were compared and analyzed. Best-fit regression model was identified. MSU dissolution times were plotted against SU at different endpoints.

RESULTS

In 29 tophaceous gout patients, MSU volume reduced from baseline 10.94 ± 10.59 cm³ to 2.87 ± 5.27 cm³ on follow-up (p = .00). Dissolution rate had a stronger correlation with SU if calculated by compound method (Pearson's correlation coefficient r= -0.77, p = .00) and was independent of baseline MSU load. The ensuing dissolution model was logarithmic and explained real-life scenarios. When SU > 0.43 mmol/l, dissolution time approached infinity. It improved to 10-19 months at SU = 0.24 mmol/l. When SU approximated zero (as with pegloticase), dissolution flattened and still took 4-8 months.

CONCLUSION

MSU dissolution is better described as a logarithmic function of SU, which explains, predicts, and facilitates understanding of the dissolution process.

The Role of a “Treat-to-Target” Approach in the Long-Term Renal Outcomes of Patients with Gout

Background: Although gout is accompanied by the substantial burden of kidney disease, there are limited data to assess renal function as a therapeutic target. This study evaluated the importance of implementing a “treat-to-target” approach in relation to renal outcomes. Methods: Patients with gout who underwent continuous urate-lowering therapy (ULT) for at least 12 months were included. The effect of ULT on renal function was investigated by means of a sequential comparison of the estimated glomerular filtration rate (eGFR). Results: Improvement in renal function was only demonstrated in subjects in whom the serum urate target of <6 mg/dL was achieved (76.40 ± 18.81 mL/min/1.73 m2 vs. 80.30 ± 20.41 mL/min/1.73 m2, p < 0.001). A significant difference in the mean change in eGFR with respect to serum urate target achievement was shown in individuals with chronic kidney disease stage 3 (−0.35 ± 3.87 mL/min/1.73 m2 vs. 5.33 ± 11.64 mL/min/1.73 m2, p = 0.019). Multivariable analysis predicted that patients ≥65 years old had a decreased likelihood of improvement (OR 0.31, 95% CI 0.13–0.75, p = 0.009). Conclusions: The “treat-to-target” approach in the long-term management of gout is associated with better renal outcomes, with a greater impact on those with impaired renal function.

Evaluation of Proposed Criteria for Remission and Evidence-Based Development of Criteria for Complete Response in Patients With Chronic Refractory Gout

Objective

The objective of this study is to assess criteria for gout remission and to use the results to inform criteria for a complete response (CR).

Methods

A post hoc analysis of two clinical trials was undertaken to determine the frequency with which subjects with chronic refractory gout who were treated with pegloticase met remission criteria. Mixed modeling was then employed to identify the components that best correlated with time to maximum benefit.

Results

Of the 56 subjects treated with biweekly pegloticase for whom adequate data were collected, 48.2% met the remission criteria. When subjects with persistent lowering of urate levels were examined separately, 27 of 32 (84.4%) met the criteria for remission. In contrast, even when the requirement for lowering of serum urate levels was waived, only 2 of 24 (8.3%) subjects without persistent lowering of urate levels and 0 of 43 subjects receiving placebo met criteria. Mixed modeling indicated that in addition to urate levels, assessment of tophi, swollen joints, and tender joints and patient global assessment best correlated with time to maximum benefit. Using these criteria of CR, 23 of the responders (71.9%) met the criteria. All patients who achieved a CR maintained it for a mean duration of 507.4 days. Finally, 64% of persistent responders to monthly pegloticase also met criteria for CR.

Conclusion

These results have validated the proposed remission criteria for gout and have helped define criteria for CR in individuals with chronic gout treated with pegloticase. This composite CR index can serve as an evidence-based target to inform the design and end points of future clinical trials.

Incident gout and chronic Kidney Disease: healthcare utilization and survival

Background

Uncontrolled gout can cause significant joint and organ damage and has been associated with impairments in quality of life and high economic cost. Gout has also been associated with other comorbid diseases, such as chronic kidney disease. The current study explored if healthcare resource utilization (HRU) and survival differs between patients with incident gout in the presence or absence of chronic kidney disease (CKD).

Methods

Clalit Health Services (CHS) data were used to conduct a retrospective population-based cohort study of incident gout between 1/1/2006–31/12/2009. Incident cases of gout were identified and stratified by CKD status and by age group (< 55 and 55+ years). CKD status was defined as a pre-existing diagnosis of chronic kidney disease, chronic renal failure, kidney transplantation, or dialysis at index date. Demographic and clinical characteristics, as well as healthcare resource use, were reported.

Results

A total of 12,940 incident adult gout patients, with (n = 8286) and without (n = 4654) CKD, were followed for 55,206 person-years. Higher rates of HRU were observed for gout patients with CKD than without. Total annual hospital admissions for patients with gout and CKD were at least 3 times higher for adults < 55 (mean = 0.51 vs 0.13) and approximately 1.5 times higher for adults 55+ (mean = 0.46 vs 0.29) without CKD. Healthcare utilization rates from year 1 to year 5 remained similar for gout patients < 55 years irrespective of CKD status, however varied according to healthcare utilization by CKD status for gout patients 55+ years. The 5-year all-cause mortality was higher among those with CKD compared to those without CKD for both age groups (HR_{< 55 years} = 1.65; 95% CI 1.01–2.71; HR_{55+ years} = 1.50; 95% CI 1.37–1.65).

Conclusions

The current study suggests important differences exist in patient characteristics and outcomes among patients with gout and CKD. Healthcare utilization differed between sub-populations, age and comorbidities, over the study period and the 5-year mortality risk was higher for gout patients with CKD, regardless of age. Future work should explore factors associated with these outcomes and barriers to gout control in order to enhance patient management among this high-risk subgroup.

Adherence and Outcomes with Urate-Lowering Therapy: A Site-Randomized Trial

PURPOSE

The purpose of this study was to test a pharmacist-led intervention to improve gout treatment adherence and outcomes.

METHODS

We conducted a site-randomized trial (n=1463 patients) comparing a 1-year, pharmacist-led intervention to usual care in patients with gout initiating allopurinol. The intervention was delivered primarily through automated telephone technology. Co-primary outcomes were the proportion of patients adherent (proportion of days covered ≥0.8) and achieving a serum urate <6.0 mg/dl at 1 year. Outcomes were reassessed at year 2.

RESULTS

Patients who underwent intervention were more likely than patients of usual care to be adherent (50% vs 37%; odds ratio [OR] 1.68; 95% confidence interval [CI] 1.30, 2.17) and reach serum urate goal (30% vs 15%; OR 2.37; 95% CI 1.83, 3.05). In the second year (1 year after the intervention ended), differences were attenuated, remaining significant for urate goal but not for adherence. The intervention was associated with a 6%-16% lower gout flare rate during year 2, but the differences did not reach statistical significance.

CONCLUSIONS

A pharmacist-led intervention incorporating automated telephone technology improved adherence and serum urate goal in patients with gout initiating allopurinol. Although this light-touch, low-tech intervention was efficacious, additional efforts are needed to enhance patient engagement in gout management and ultimately to improve outcomes.

Verinurad combined with febuxostat in Japanese adults with gout or asymptomatic hyperuricaemia: a phase 2a, open-label study

Objectives

Verinurad (RDEA3170) is a high-affinity inhibitor of the URAT1 transporter in clinical development for treating gout and asymptomatic hyperuricaemia. The aim of this Phase 2a, randomized, open-label study was to investigate the multiple-dose pharmacodynamics, pharmacokinetics and safety of oral verinurad combined with febuxostat vs febuxostat alone and verinurad alone.

Methods

Japanese male subjects aged 21–65 years with gout (n = 37) or asymptomatic hyperuricaemia (n = 35) and serum urate (sUA) ⩾8 mg/dl were randomized to febuxostat (10, 20, 40 mg) in combination with verinurad (2.5–10 mg), verinurad alone (2.5–15 mg), febuxostat alone (10, 20, 40 mg) or benzbromarone alone (50 mg). There were four treatment periods per cohort and each treatment period was 7 days. Study drugs were administered once-daily after breakfast. Plasma, serum and urine samples were measured at pre-set intervals on days –1, 7, 14, 21 and 28.

Results

Verinurad combined with febuxostat decreased sUA in dose-dependent manner, providing greater sUA lowering than febuxostat alone at the same dose (P < 0.001). Urinary uric acid excretion rate was increased by verinurad, reduced by febuxostat and comparable to baseline for verinurad combined with febuxostat. Verinurad from 2.5 mg to 15 mg was well tolerated, with no withdrawals due to adverse events. Laboratory assessments showed no clinically meaningful changes during combination treatment.

Conclusion

Verinurad combined with febuxostat decreased sUA dose-dependently while maintaining uric acid excretion similar to baseline. All dose combinations of verinurad and febuxostat were generally well tolerated. These data support continued investigation of oral verinurad in patients with gout.

Trial registration

ClinicalTrials.gov, https://clinicaltrials.gov, NCT02317861

Effect of Renal Impairment on the Pharmacokinetics and Pharmacodynamics of Verinurad, a Selective Uric Acid Reabsorption Inhibitor

BACKGROUND AND OBJECTIVE: Verinurad (RDEA3170) is a high-affinity, selective URAT1 transporter inhibitor in development for treating gout and asymptomatic hyperuricemia. This Phase I, single-dose study investigated the pharmacokinetics, pharmacodynamics, and safety of verinurad in adults with renal impairment and controls with normal renal function.

METHODS

Males aged 18-85 years were enrolled with serum urate (sUA) 4.5-10 mg/dl and creatinine clearance 60- < 90, 30- < 60, 15- < 30, or ≥ 90 ml/min (mild, moderate, severe renal impairment and controls, respectively; n = 7/8). Verinurad 15 mg was administered orally under fasted conditions. Serial plasma/serum and urine samplings were 30 min pre-dose to 72 h post-dose.

RESULTS

Compared to controls, verinurad maximum observed plasma concentration increased by 53, 73, and 128% and area under the concentration-time curve increased by 24, 148, and 130%, in subjects with mild, moderate, and severe renal impairment, respectively; renal clearance decreased by 5, 42, and 79%. Exposures of major verinurad metabolites also increased with increasing renal impairment. Verinurad decreased sUA in all groups, with greater maximal changes in control and mild renal impairment than moderate and severe impairment groups (- 38.3, - 36.9, - 20.5, - 12.6%, respectively). There were no adverse event-related withdrawals or clinically meaningful changes in laboratory values.

CONCLUSION

Exposures of verinurad and metabolites increased with decreasing renal function. Consistent with the renal-dependent mechanism of action of verinurad, increasing severity of renal impairment was associated with decreased sUA lowering. Verinurad safety assessments were similar regardless of renal impairment. Continued investigation of verinurad is warranted in patients with gout and renal impairment. CLINICALTRIALS.

GOV IDENTIFIER

NCT02219516.

Pharmacokinetics, Pharmacodynamics, and Tolerability of Concomitant Multiple Dose Administration of Verinurad (RDEA3170) and Allopurinol in Adult Male Subjects With Gout

Verinurad (RDEA3170) is a selective uric acid reabsorption inhibitor in clinical development for treatment of hyperuricemia and gout. This phase 1b, multiple‐dose, drug‐drug interaction study evaluated the pharmacokinetics, pharmacodynamics, and tolerability of verinurad in combination with allopurinol. Adult males with gout were randomized to receive once‐daily oral doses of allopurinol 300 mg or verinurad 10 mg alone for 7 days, allopurinol 300 mg + verinurad 10 mg on days 8 to 14, and the alternative single agent on days 15 to 21. Colchicine 0.6 mg was taken prophylactically for gout flares. Plasma/serum and urine samples were assayed for verinurad, allopurinol, oxypurinol (allopurinol active metabolite), colchicine (plasma only), and uric acid. Safety was assessed by adverse events (AEs) and laboratory tests. Verinurad plasma exposure was unaffected by allopurinol. Verinurad increased the maximum observed plasma concentration (C_max) for allopurinol by 33%; the area under the plasma concentration‐time curve (AUC) was unaffected. Oxypurinol C_max and AUC were reduced 32% and 38%, respectively, by verinurad. Colchicine plasma exposure was unaltered by verinurad. The maximum decrease in serum urate was greater with verinurad + allopurinol (65%) than with verinurad (51%) or allopurinol (43%) alone. Compared with the baseline rate, the maximum rate of uric acid excreted in urine was +56% with verinurad, −46% with allopurinol, and unchanged with verinurad + allopurinol. No serious AEs, discontinuations due to AEs, or clinically significant laboratory abnormalities were noted. Despite decreased systemic exposure of allopurinol and oxypurinol in the presence of verinurad, the combination resulted in greater serum urate reduction compared with either drug alone and was well tolerated at the studied doses.

Pharmacokinetics, Pharmacodynamics, and Tolerability of Concomitant Administration of Verinurad and Febuxostat in Healthy Male Volunteers

Verinurad (RDEA3170) is a selective uric acid reabsorption inhibitor in development for treatment of gout and asymptomatic hyperuricemia. This phase 1, single-blind, multiple-dose, drug-drug interaction study evaluated the pharmacokinetics (PK), pharmacodynamics, and safety/tolerability of verinurad in combination with febuxostat in healthy male volunteers. Twenty-three subjects were randomized and received once-daily doses of verinurad (or placebo) or febuxostat alone (days 1-7 and days 15-21), or verinurad + febuxostat on days 8-14. For combinations, subjects received verinurad 10 mg + febuxostat 40 mg or verinurad 2.5 mg + febuxostat 80 mg. Plasma/serum and urine samples were analyzed for verinurad, febuxostat, and uric acid. Safety was assessed by adverse events and laboratory tests. Febuxostat 40 mg had no effect on plasma exposure of verinurad 10 mg, whereas febuxostat 80 mg increased the maximum observed plasma concentration and the area under the plasma concentration-time curve of verinurad 2.5 mg by 25% and 33%, respectively. Verinurad had no effect on febuxostat PK. Maximal reduction in serum urate was 76% with verinurad 10 mg + febuxostat 40 mg versus verinurad 10 mg (56%) or febuxostat 40 mg (49%) alone and was 67% with verinurad 2.5 mg + febuxostat 80 mg versus verinurad 2.5 mg (38%) or febuxostat 80 mg (57%) alone. Verinurad increased, whereas febuxostat decreased, 24-hour fractional excretion and renal clearance of uric acid. There was no clinically significant drug-drug interaction between verinurad and febuxostat PK. The combination resulted in greater reductions of serum urate than either drug alone and was well tolerated at the studied doses.

Pharmacodynamic and pharmacokinetic effects and safety of verinurad in combination with febuxostat in adults with gout: a phase IIa, open-label study

OBJECTIVE

Verinurad (RDEA3170) is a high-affinity, selective URAT1 inhibitor in development for treating gout and asymptomatic hyperuricaemia. This study evaluated the pharmacodynamics, pharmacokinetics and safety of verinurad in combination with febuxostat in adults with gout.

METHODS

The phase IIa, open-label, multicentre study randomised 64 subjects into one of five cohorts to receive febuxostat (40 or 80 mg) alone or in combination with verinurad 2.5-20 mg. Serial plasma/serum and urine samples were assayed for verinurad and uric acid. Safety was assessed by adverse events, chemistry panels, ECGs and physical examinations.

RESULTS

Serum pharmacodynamic data demonstrated the maximum percent decrease in serum urate (sUA) from baseline (Emax) at 8-12 hours after dosing. Verinurad with febuxostat decreased sUA in a dose-dependent manner. Emax for verinurad with febuxostat 40 mg ranged from 52% to 77% vs 42% for febuxostat 40 mg alone; Emax for verinurad with febuxostat 80 mg was 62%-82% vs 55% for febuxostat 80 mg alone. Urinary uric acid excretion rate was reduced below baseline by febuxostat alone and was comparable to baseline for verinurad with febuxostat. Verinurad plasma exposure increased with dose and was comparable when combined with febuxostat. No drug-drug interactions were observed. Verinurad was well tolerated with no clinically meaningful changes in laboratory values.

CONCLUSION

Verinurad administered with febuxostat produced dose-dependent decreases in sUA while maintaining urinary uric acid levels comparable to baseline. These dose combinations of verinurad and febuxostat were generally well tolerated. These data support continued investigation of oral verinurad in patients with gout.

TRIAL REGISTRATION NUMBER

NCT02246673.

Pharmacodynamic and pharmacokinetic effects and safety of verinurad in combination with allopurinol in adults with gout: a phase IIa, open-label study

Objectives

Verinurad (RDEA3170) is a high affinity, selective uric acid transporter (URAT1) inhibitor indevelopment for treating gout and asymptomatic hyperuricaemia. This phase IIa study evaluated the pharmacodynamics, pharmacokinetics and safety of verinurad combined with allopurinol versus allopurinol alone in adults with gout.

Methods

Forty-one subjects were randomised into two cohorts of verinurad (2.5-20 mg) plus allopurinol (300 mg once daily) versus allopurinol 300 mg once daily, 600 mg once daily or 300 mg twice daily alone. Each treatment period was 7 days. Serial plasma/serum and urine samples were assayed for verinurad, allopurinol, oxypurinol and uric acid.

Results

Serum pharmacodynamic data pooled across cohorts demonstrated maximum per cent decreases in serum urate (sUA) from baseline (E_max) at 7-12 hours after verinurad plus allopurinol treatment. Combination treatment decreased sUA in dose-dependent manner: least-squares means E_max was 47%, 59%, 60%, 67%, 68% and 74% for verinurad doses 2.5, 5, 7.5, 10, 15 and 20 mg plus allopurinol 300 mg once daily, versus 40%, 54% and 54% for allopurinol 300 mg once daily, 600 mg once daily and 300 mg twice daily. Verinurad had no effect on allopurinol plasma pharmacokinetics, but decreased oxypurinol C_max by 19.0%-32.4% and area under the plasma concentration-time curve from time zero to the last measurable time point by 20.8%-39.2%. Verinurad plus allopurinol was well tolerated with no serious adverse events (AEs), AE-related withdrawals or renal-related events. Laboratory values showed no clinically meaningful changes.

Conclusion

Verinurad coadministered with allopurinol produced dose-dependent decreases in sUA. All dose combinations of verinurad and allopurinol were generally well tolerated. These data support continued investigation of oral verinurad in patients with gout.

Trial registration number

NCT02498652.

Gouty arthritis: decision-making following dual-energy CT scan in clinical practice, a retrospective analysis

To establish whether dual-energy CT (DECT) is a diagnostic tool, i.e., associated with initiation or discontinuation of a urate lowering drug (ULD). Secondly, to determine whether DECT results (gout deposition y/n) can be predicted by clinical and laboratory variables. Digital medical records of 147 consecutive patients with clinical suspicion of gout were analyzed retrospectively. Clinical data including medication before and after DECT, lab results, and results from diagnostic joint aspiration and DECT were collected. The relationship between DECT results and clinical and laboratory results was evaluated by univariate regression analyses; predictors showing a p < 0.10 were entered in a multivariate logistic regression model with the DECT result as outcome variable. A backward stepwise technique was applied. After the DECT, 104 of these patients had a clinical diagnosis of gout based on the clinical judgment of the rheumatologist, and in 84 of these patients, the diagnosis was confirmed by demonstration of monosodium urate (MSU) crystals in synovial fluid (SF) or by positive DECT. After DECT, the current ULD was modified in 33 (22.4%) of patients; in 29 of them, ULD was started and in 1 it was intensified. Following DECT, the current ULD was stopped in three patients. In the multivariable regression model, cardiovascular disease (OR 3.07, 95% CI 1.26-7.47), disease duration (OR 1.008, 95% CI 1.001-1.016), frequency of attack (OR 1.23, 95% CI 1.07-1.42), and creatinine clearance (OR 2.03, 95% CI 0.91-1.00) were independently associated with positive DECT results. We found that the DECT result increases the confidence of the prescribers in their decision to initiation or discontinuation of urate lowering therapy regimen in of mono- or oligoarthritis. It may be a useful imaging tool for patients who cannot undergo joint aspiration because of contraindications or with difficult to aspirate joints, or those who refuse joint aspiration. We also suggest the use of DECT in cases where a definitive diagnosis cannot be made from signs, symptoms, and MSU analysis alone.

What Outcomes are Important for Gout Patients? In-Depth Qualitative Research into the Gout Patient Experience to Determine Optimal Endpoints for Evaluating Therapeutic Interventions

Background and Objectives

Characterized by sudden onset of severe joint pain, swelling, redness, and tenderness to touch, gout ‘flare ups’ have a substantial impact on quality of life (QoL). This research employed a patient-centered approach to explore the symptoms and impacts of gout, and assess the content validity of existing patient-reported outcomes (PROs).

Methods

Qualitative interviews were conducted with 30 US gout patients (non-tophaceous: n = 20, tophaceous: n = 10) and five expert rheumatologists. Each interview included both concept elicitation (CE) questioning to learn about the patient experience and cognitive debriefing to assess the content validity of three PRO instruments (HAQ-DI, GAQ, and TIQ-20). Nine of the patients provided further real-time qualitative data through a smart phone application. All qualitative data were subject to thematic analysis using Atlas.ti. Two patient advisors and three expert clinicians were engaged as advisors at key stages throughout the research.

Results

Interview and real-time data identified the same core symptoms and proximal impact concepts. Severe pain (typically in joints of extremities) was described as the cardinal symptom, often accompanied by swelling, redness, heat, sensitivity to touch, and stiffness. Domains of QoL impacted included physical functioning, sleep, daily activities, and work. The PRO instruments were generally well-understood by patients, but each included items with questionable relevance to at least some of the sample, dependent on the specific joints affected.

Conclusions

Gout patients experience severe pain in affected joints, resulting in substantial limitations in physical functioning. Both the HAQ-DI and the TIQ-20 are useful for specific research purposes in the gout population, although modifications are recommended.

Electronic supplementary material

The online version of this article (doi:10.1007/s40271-016-0184-x) contains supplementary material, which is available to authorized users.

Stepwise dose increase of febuxostat is comparable with colchicine prophylaxis for the prevention of gout flares during the initial phase of urate-lowering therapy: results from FORTUNE-1, a prospective, multicentre randomised study

Objectives

To determine whether febuxostat with stepwise dose increase is as useful as colchicine prophylaxis in reducing gout flares during the initial introduction of urate-lowering therapy in patients with gout in comparison with febuxostat with no dose titration.

Methods

In this prospective, multicentre, randomised open-label comparative study, patients were randomised to group A (stepwise dose increase of febuxostat from 10 to 40 mg/day), group B (fixed-dose febuxostat 40 mg/day plus colchicine 0.5 mg/day) or group C (fixed-dose febuxostat 40 mg/day) and observed for 12 weeks. Gout flare was defined as non-steroidal anti-inflammatory drug use for gout symptoms.

Results

A total of 255 patients were randomised, and 241 patients were treated. Among the treated patients, gout flares were experienced by 20/96 (20.8%) in group A, 18/95 (18.9%) in group B and 18/50 (36.0%) in group C. The incidence of flare was significantly lower in groups A and B than that in group C (P=0.047 and P=0.024, respectively), although the differences were not significant after correction for multiple comparisons. No significant difference was noted between the incidence of gout flare in groups A and B.

Conclusions

Our data suggested that stepwise dose increase of febuxostat and low-dose colchicine prophylaxis effectively reduced gout flares in comparison with fixed-dose febuxostat alone. Stepwise dose increase of febuxostat may be an effective alternative to low-dose colchicine prophylaxis during the introduction of urate-lowering therapy.

Trial registration number

UMIN 000008414.

Predictors of reaching a serum uric acid goal in patients with gout and treated with febuxostat

Purpose

Clinical guidelines recommend febuxostat as first-line pharmacologic urate-lowering therapy for patients with gout to achieve a goal serum uric acid (sUA) <6 mg/dL; however, little is known about other contributing factors. This study identified clinical characteristics of patients treated with febuxostat to develop and validate a predictive model for achieving a goal sUA.

Patients and methods

Patients with Humana Medicare or commercial insurance, diagnosed with gout and newly initiated on febuxostat (index date February 1, 2009 – December 31, 2013), were identified for a retrospective cohort study. Patients were followed for 365 days and the first valid sUA test result ≥120 days after index was retained. A stepwise logistic regression with backward elimination was estimated to model sUA goal attainment, and a linear model was estimated to model the impact of predictor variables on sUA level.

Results

The study sample (n=678) was divided into a development (training) dataset (n=453) and a validation (holdout) dataset (n=225). In the training sample, patients in the sUA <6 mg/dL group were on febuxostat for a longer time, were more adherent, and had a lower average base-line sUA level (all p<0.0001) vs patients in the sUA ≥6 mg/dL group. In the logistic model, febuxostat adherence (odds ratio [OR]=1.03, p<0.0001) and baseline sUA level (OR=0.84, p<0.0001) increased the odds of attaining sUA <6 mg/dL. In the linear regression model, increase in febuxostat adherence (p<0.0001), baseline sUA level (p<0.0001), advanced age (p=0.0021), and not having congestive heart failure (p<0.05) were associated with a reduction of sUA level. Pre-index allopurinol use was a marginally significant predictor of sUA level reduction (p=0.06).

Conclusions

Among febuxostat users diagnosed with gout in a real-world setting, adherence to febuxostat and lower baseline sUA level were the strongest predictors of attaining sUA goal. These findings may help clinicians to identify appropriate patients most likely to benefit from febuxostat treatment, and underscore the importance of medication adherence in this challenging patient population.

The Duality of Economic Issues With Medication Non-adherence in Patients With Inflammatory Arthritis

PURPOSE OF REVIEW

In this review, we synthesize current data on non-adherence across inflammatory arthritides and explore (1) the effects of economic factors on non-adherence and (2) the impacts of non-adherence on economic outcomes.

RECENT FINDINGS

Recent evidence demonstrates medication non-adherence rates as high as 74% in ankylosing spondylitis (AS), 90% in gout, 50% in psoriatic arthritis (PsA), 75% in systemic lupus erythematosus (SLE), and 82% in rheumatoid arthritis (RA). The effects of socioeconomic factors have been studied most in RA and SLE but with inconsistent findings. Nonetheless, the evidence points to having prescription coverage and costs of treatment as important factors in RA and education as an important factor in SLE. Limited data in AS and gout, and no studies of the effects of socioeconomic factors in PsA, show knowledge gaps for future research. Finally, there is a dearth of data with respect to the impacts of non-adherence on economic outcomes.

Xanthine oxidoreductase and its inhibitors: relevance for gout

Xanthine oxidoreductase (XOR) is the rate-limiting enzyme in purine catabolism and converts hypoxanthine to xanthine, and xanthine into uric acid. When concentrations of uric acid exceed its biochemical saturation point, crystals of uric acid, in the form of monosodium urate, emerge and can predispose an individual to gout, the commonest form of inflammatory arthritis in men aged over 40 years. XOR inhibitors are primarily used in the treatment of gout, reducing the formation of uric acid and thereby, preventing the formation of monosodium urate crystals. Allopurinol is established as first-line therapy for gout; a newer alternative, febuxostat, is used in patients unable to tolerate allopurinol. This review provides an overview of gout, a detailed analysis of the structure and function of XOR, discussion on the pharmacokinetics and pharmacodynamics of XOR inhibitors-allopurinol and febuxostat, and the relevance of XOR in common comorbidities of gout.

Quality of care in gout: a clinical audit on treating to the target with urate lowering therapy in real-world gout patients

The current paper aimed to describe the quality of care for gout patients by showing the clinical outcomes achieved in two patient cohorts in which differing targeted urate lowering therapy (ULT) treatment approaches were employed, both aiming to reach the European League Against Rheumatism recommended serum urate (sUA) targets. A retrospective medical chart review study was conducted. Data from the medical records of gout patients from two clinical centers in The Netherlands, both applying targeted ULT treatments (albeit using different approaches), were reviewed. Patients in cohort A were given a combination of xanthine oxidase inhibitors with uricosurics if treatment with allopurinol monotherapy failed to reach sUA target levels, whereas patients in cohort B were treated with sequential monotherapy. Data on patient characteristics and clinical outcomes were collected. A total of 177 patient dossiers were included: 99 from cohort A and 78 from cohort B. The great majority (n = 146, 82.5%) of the patients in both cohorts had a current sUA level <360 µmol/L. In addition, more than half (n = 104, 58.8%) of the patients met the stringent sUA target level of <300 µmol/L. The largest reductions in mean sUA levels were observed for patients who were treated with combination therapy. This clinical audit of two cohorts of gout patients provides initial—yet promising—results regarding the proportion of real-world gout patients in whom recommended that sUA target levels can be achieved, and demonstrates the added value that a targeted treatment approach may have in reaching these goals.

Serum Uric Acid and the Risk of Incident and Recurrent Gout: A Systematic Review

OBJECTIVE

Lowering serum uric acid (SUA) levels can essentially cure gout; however, this is not widely practiced. To summarize epidemiologic evidence related to this causal link, we conducted a systematic review of the published literature reporting the association between SUA level and incident and recurrent gout (i.e., gout flares).

METHODS

We systematically searched Medline, EMBASE, and the Cochrane Database of Systematic Reviews using separate search strategies for incident gout and recurrent gout. We screened 646 abstracts to identify 8 eligible articles reporting gout incidence and 913 abstracts to identify 18 articles reporting recurrent gout.

RESULTS

For both gout incidence and recurrence, a graded trend was observed where the risk was increased with higher SUA levels. Gout incidence rates per 1000 person-years from population-based studies ranged from 0.8 (SUA ≤ 6 mg/dl) to 70.2 cases (SUA ≥ 10 mg/dl). Recurrent gout risk in clinical cohorts ranged from 12% (SUA ≤ 6 mg/dl) to 61% (SUA ≥ 9 mg/dl) among those receiving urate-lowering therapy (ULT), and 3.7% (SUA 6-7 mg/dl) to 61% (SUA > 9.3 mg/dl) after successful ULT. Retrospective database studies also showed a graded relationship, although the strength of the association was weaker. Studies reporting mean flares or time-to-flare according to SUA showed similar findings.

CONCLUSION

This systematic review confirms that higher SUA levels are associated with increased risk of incident and recurrent gout in a graded manner. Although few prospective cohorts have evaluated incident and recurrent gout according to SUA, the existing evidence underscores the need to treat to SUA targets, as recommended by the American College of Rheumatology and the European League Against Rheumatism.

Treatment approaches and adherence to urate-lowering therapy for patients with gout

Gout is the most common inflammatory arthritis characterized by painful disabling acute attacks. It is caused by hyperuricemia and deposition of urate crystals in and around the joints. Long-standing untreated hyperuricemia can lead to chronic arthritis with joint damage, tophi formation and urate nephropathy. Gout is associated with significant morbidity and health care associated cost. The goal of long-term therapy is to lower the serum urate level to promote dissolution of urate crystals, reduce recurrent acute gout flares, resolve tophi and prevent joint damage. Despite the presence of established gout treatment guidelines and effective medications to manage gout, patient outcomes are often poor. Etiology for these shortcomings is multifactorial including both physician and patient characteristics. Poor adherence to urate-lowering therapy (ULT) is prevalent and is a significant contributor to poor patient outcomes. This article reviews the treatment strategies for the management of hyperuricemia in chronic gout, gaps in quality of care in gout management, factors contributing to poor adherence to ULT and discusses potential interventions to achieve improved gout-related outcomes. These interventions include initiation of prophylactic anti-inflammatory medication when starting ULT, frequent follow-ups, regular serum urate monitoring and improved patient education, which can be achieved through pharmacist- or nurse-assisted programs. Interventions such as these could improve adherence to ULT and, ultimately, result in optimal gout-related outcomes.

Pilot study of a multidisciplinary gout patient education and monitoring program

OBJECTIVE

Gout patient self-management knowledge and adherence to treatment regimens are poor. Our objective was to assess the feasibility and acceptability of a multidisciplinary team-based pilot program for the education and monitoring of gout patients.

METHODS

Subjects completed a gout self-management knowledge exam, along with gout flare history and compliance questionnaires, at enrollment and at 6 and 12 months. Each exam was followed by a nursing educational intervention via a structured gout curriculum. Structured monthly follow-up calls from pharmacists emphasized adherence to management programs. Primary outcomes were subject and provider program evaluation questionnaires at 6 and 12 months, program retention rate and success in reaching patients via monthly calls.

RESULTS

Overall, 40/45 subjects remained in the study at 12 months. At 12 months, on a scale of 1 (most) to 5 (least), ratings of 3 or better were given by 84.6% of subjects evaluating the usefulness of the overall program in understanding and managing their gout, 81.0% of subjects evaluating the helpfulness of the nursing education program, and 50.0% of subjects evaluating the helpfulness of the calls from the pharmacists. Knowledge exam questions that were most frequently answered incorrectly on repeat testing concerned bridge therapy, the possibility of being flare-free, and the genetic component of gout.

CONCLUSIONS

Our multidisciplinary program of gout patient education and monitoring demonstrates feasibility and acceptability. We identified variability in patient preference for components of the program and persistent patient knowledge gaps.

Gout

Gout is a chronic disease of deposition of monosodium urate crystals, which form in the presence of increased urate concentrations. Although environmental factors contribute to hyperuricaemia, renal and gut excretion of urate is central to regulation of serum urate, and genetic factors are important. Activation of the NLRP3 inflammasome and release of interleukin 1β have key roles in initiation of acute gout flares. A "treat to target serum urate" approach is essential for effective gout management; long-term lowering of serum urate to less than 360 μmol/L leads to crystal dissolution and ultimately to suppression of flares. An allopurinol dose-escalation strategy is frequently effective for achieving treatment targets, and several new urate-lowering drugs are also available. Worldwide, rates of initiation and continuation of urate-lowering therapy are very low, and, consequently, achievement of serum urate targets is infrequent. Strategies to improve quality of gout care are needed.

Decrystallization of Crystals Using Gold "Nano-Bullets" and the Metal-Assisted and Microwave-Accelerated Decrystallization Technique

Gout is caused by the overproduction of uric acid and the inefficient metabolism of dietary purines in humans. Current treatments of gout, which include anti-inflammatory drugs, cyclooxygenase-2 inhibitors, and systemic glucocorticoids, have harmful side-effects. Our research laboratory has recently introduced an innovative approach for the decrystallization of biological and chemical crystals using the Metal-Assisted and Microwave-Accelerated Evaporative Decrystallization (MAMAD) technique. In the MAMAD technique, microwave energy is used to heat and activate gold nanoparticles that behave as “nano-bullets” to rapidly disrupt the crystal structure of biological crystals placed on planar surfaces. In this study, crystals of various sizes and compositions were studied as models for tophaceous gout at different stages (i.e., uric acid as small crystals (~10–100 μm) and l-alanine as medium (~300 μm) and large crystals (~4400 μm). Our results showed that the use of the MAMAD technique resulted in the reduction of the size and number of uric acid and l-alanine crystals up to >40% when exposed to intermittent microwave heating (up to 20 W power at 8 GHz) in the presence of 20 nm gold nanoparticles up to 120 s. This study demonstrates that the MAMAD technique can be potentially used as an alternative therapeutic method for the treatment of gout by effective decrystallization of large crystals, similar in size to those that often occur in gout.

Development and First Validation of a Disease Activity Score for Gout

Objective

To develop a new composite disease activity score for gout and provide its first validation.

Methods

Disease activity has been defined as the ongoing presence of urate deposits that lead to acute arthritis and joint damage. Every measure for each Outcome Measures in Rheumatology core domain was considered. A 3‐step approach (factor analysis, linear discriminant analysis, and linear regression) was applied to derive the Gout Activity Score (GAS). Decision to change treatment or 6‐month flare count were used as the surrogate criteria of high disease activity. Baseline and 12‐month followup data of 446 patients included in the Kick‐Off of the Italian Network for Gout cohort were used. Construct‐ and criterion‐related validity were tested. External validation on an independent sample is reported.

Results

Factor analysis identified 5 factors: patient‐reported outcomes, joint examination, flares, tophi, and serum uric acid (sUA). Discriminant function analysis resulted in a correct classification of 79%. Linear regression analysis identified a first candidate GAS including 12‐month flare count, sUA, visual analog scale (VAS) of pain, VAS global activity assessment, swollen and tender joint counts, and a cumulative measure of tophi. Alternative scores were also developed. The developed GAS demonstrated a good correlation with functional disability (criterion validity) and discrimination between patient‐ and physician‐reported measures of active disease (construct validity). The results were reproduced in the external sample.

Conclusion

This study developed and validated a composite measure of disease activity in gout. Further testing is required to confirm its generalizability, responsiveness, and usefulness in assisting with clinical decisions.

Temporal evolution of urate crystal deposition over articular cartilage after successful urate-lowering therapy in patients with gout: An ultrasonographic perspective

OBJECTIVE

To detect evolution of ultrasonographic signs of deposition of monosodium urate crystals (MSUC) in gouty joints by serial ultrasonography after initiation of urate-lowering therapy (ULT).

METHODS

Adult gout patients were examined by serial ultrasonography after initiation of ULT with target serum uric acid (SUA) < 6 mg/dL.

RESULTS

Thirty-eight male patients with gout with mean age of 50 ± 11 years, median disease duration of 48 months and baseline mean SUA level of 8.8 ± 1.5 mg/dL were recruited. Ultrasonographic evidence of MSUC deposition was detected in 89.74% of first metatarsophalangeal (MTP) joints and 27.63% of knee joints. Double contour sign (DCS), tophi, and hyperechoic spots (HES) were detected in 77.63%, 43.42%, and 19.74% of first MTPs, respectively. SUA level normalizes and plateaus after fourth month of follow-up. DCS thickness reduced significantly throughout the follow-up period. Overall, 86.25% DCS and 100% HES disappeared with median time of 6 months and 5.7 months, respectively. SUA normalization was the only significant predictor of DCS disappearance.

CONCLUSIONS

Serial ultrasonographic determination of DCS, tophi, or HES during hypouricemic therapy is a noninvasive, effective method to detect the lowering of burden of urate load in gouty joints.

Rationale and design of the randomized evaluation of an Ambulatory Care Pharmacist-Led Intervention to Optimize Urate Lowering Pathways (RAmP-UP) Study

BACKGROUND

Despite the availability of effective therapies, most gout patients achieve suboptimal treatment outcomes. Current best practices suggest gradual dose-escalation of urate lowering therapy and serial serum urate (sUA) measurement to achieve sUA<6.0mg/dl. However, this strategy is not routinely used. Here we present the study design rationale and development for a pharmacist-led intervention to promote sUA goal attainment.

METHODS

To overcome barriers in achieving optimal outcomes, we planned and implemented the Randomized Evaluation of an Ambulatory Care Pharmacist-Led Intervention to Optimize Urate Lowering Pathways (RAmP-UP) study. This is a large pragmatic cluster-randomized trial designed to assess a highly automated, pharmacist-led intervention to optimize allopurinol treatment in gout. Ambulatory clinics (n=101) from a large health system were randomized to deliver either the pharmacist-led intervention or usual care to gout patients over the age of 18years newly initiating allopurinol. All participants received educational materials and could opt-out of the study. For intervention sites, pharmacists conducted outreach primarily via an automated telephone interactive voice recognition system. The outreach, guided by a gout care algorithm developed for this study, systematically promoted adherence assessment, facilitated sUA testing, provided education, and adjusted allopurinol dosing. The primary study outcomes are achievement of sUA<6.0mg/dl and treatment adherence determined after one year. With follow-up ongoing, study results will be reported subsequently.

CONCLUSION

Ambulatory care pharmacists and automated calling technology represent potentially important, underutilized resources for improving health outcomes for gout patients.

In Vitro and In Vivo Interaction Studies Between Lesinurad, a Selective Urate Reabsorption Inhibitor, and Major Liver or Kidney Transporters

BACKGROUND AND OBJECTIVES

Lesinurad is a selective uric acid reabsorption inhibitor (SURI) under investigation for the treatment of gout. This study elucidated the interaction of lesinurad with major liver and kidney transporters in vitro and evaluated the drug-drug interactions (DDIs) of lesinurad and atorvastatin, metformin, and furosemide in clinical studies.

METHODS

Lesinurad interaction with membrane transporters was evaluated in validated transporter-expressing cell systems and analyzed by liquid scintillation counting. Healthy male subjects (ages 18-65 years; body mass index 18-32 kg/m(2)) received atorvastatin (40 mg; n = 28) with or without lesinurad 200 or 400 mg, or received metformin (850 mg; n = 12) or furosemide (40 mg; n = 11) with or without lesinurad 400 mg. Plasma concentrations of each concomitant drug were determined by validated liquid chromatography with tandem mass spectrometry methods.

RESULTS

Lesinurad interacted in vitro with OATP1B1, OCT1, and OAT1/3 transporters. Co-administration of lesinurad 200 mg did not significantly alter plasma exposure (maximum concentration [C max] and area under the concentration-time curve [AUC]) of total atorvastatin (atorvastatin + hydroxyl-metabolites) or atorvastatin, while co-administration of lesinurad 400 mg increased the C max of total atorvastatin and atorvastatin by 17-26 %, but had no effect on AUC. Co-administration of lesinurad 400 mg had no effect on the plasma exposure of metformin. Furosemide plasma AUC was reduced by 31 % in the presence of lesinurad 400 mg, but furosemide renal clearance and diuretic activity were unchanged.

CONCLUSIONS

No clinically relevant DDIs were observed between lesinurad and substrates of major liver or kidney transporters.